1. Field of the Invention
This invention relates to apparatus for preventing flooding as a result of leakage from a water heater located in a building, and more particularly concerns apparatus for detecting such leakage and shutting off water flow to the leaking water heater.
2. Description of the Prior Art
Water heaters, whether in residential or commercial buildings, are susceptible to failure in a manner wherein the water within the heater and water entering the heater will leak uncontrollably onto the underlying floor. Such flooding could cause extensive damage to the building and its contents.
U.S. Pat. No. 6,543,471 describes a spring operated fail safe mechanism which, in response to the rising of a float device within a collecting pan beneath a water heater, causes a trigger mechanism to close a valve that supplies water to said heater. However, said spring mechanism requires a tether line that extends to an operating lever of the valve, and such arrangement compromises reliability. Also, the trigger mechanism involves the sliding removal of a locking post from a close-fitting bore. Such arrangement is subject to malfunction due to effects of corrosion and dirt accumulation.
U.S. Pat. No. 6,895,990 concerns a fail safe device similar to that of U.S. Pat. No. 6,543,471, but employs a valve having a drive rod that is spring driven upwardly for closure. The trigger mechanism employs a lever manipulated cam that maintains force upon the top of the drive rod to keep it down, thereby producing the open state of the valve.
Because the cam has a pointed activating tip adapted to engage the top of the drive rod, it is difficult to position said tip in a stable state upon the top of the drive rod. Any error in such positioning procedure is dangerous to the user because of the forceful motion that can be applied to the lever portion of the cam by the spring that activates the drive rod.
It is accordingly an object of the present invention to provide apparatus of improved reliability for automatically preventing flooding that might be produced by a faulty water heater.
It is a further object of this invention to provide apparatus as in the foregoing object having a trigger mechanism which can be easily and safely manipulated.
It is another object of the present invention to provide apparatus of the aforesaid nature of durable, trouble-free construction and amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.